Stepmom comes into your room to talk. You've always been close. She tells you your dad has filed for divorce, all so he can be with that bimbo Barbie whore with the fake tits! Stepmom will lose everything in the divorce... unless.... you knock her up, and we tell the court it's your dad's so you and stepmom will still get lots of money for the next 20ish years! Stepmom knows this isn't exactly legal or moral but it's not like you haven't wanted to get your cock wet with stepmommy's juices... she knows you've been fantasizing about her the last 5 years, so it doesn't take much seducing before you're balls deep inside her giving her exactly what she wants!